Thanks to the wonderful folks at White Pine tech support, and a lot of
great suggestions from this list serve, I am happily running White Pine
CU and Internet Phone 4.5 on the same machine without any conflicts or
general protection faults. The problem was two-fold, and I am providing
this information to the list in case anyone else runs into the same
problem:

(1) Version 2.x of White Pine CU copies a version of msvcrt.dll to the
/windows/system directory which is not compliant with the version of
msvcrt.dll needed to run Internet Phone 4.5. Because of the new dll
file, IPhone 4.5 could not work properly... the solution to this it to
upgrade White Pine CU to version 3.1 (available now from the web for
trial purposes). Just a general note: Internet Phone 5.0 does not
experience this conflict.

(b) An application which was running in the background of my machine was
causing some slow down of my system due to the RAM it required (Lotus
Smart Suite's toolbar). I have since removed the toolbar from running
in the background, and CU is running fine.

In fact, thanks to the recommendations of white pine tech support and
various members of this list, things are running better than ever.

Just a warning tho... do not run CUSeeMe 2.11 and Internet Phone 4.5 on
the same machine, as you will run into version conflicts as I did.
Version 3.1 of CU, version 5.0 of Internet Phone, and Cornell's CU do
not experience these same problems.